[Integration of additional (rotary) axis to modified Ender-3 printer]

Hello, 

I am doing a project on integrating a additional (rotary axis) to ender-3 printer i replaced motherboard with MKS GEN L V2.. In my motherboard there are 5 motor drivers designated for X,Y,Z,E0,E1 now the first four are occupied and E1 is left, can i use it to integrate my rotary axis? If yes how to configure my marlin firmware by repurposing E1 driver according to it?

[Slicing and generating G-code for custom Additional(rotary) axis to print supportless springs in ender-3 printer]

Hello,

I am developing a project to integrate a additional axis(rotary) to ender-3 printer. Now my problem is slicing, as general slicing softwares eg;Cura is restricted for Cartesian co-ordinates

So how can i generate Custom G-code for printing on rotary axis. Is there any software or methods available?